Whisk flour, brown sugar, baking powder, and pumpkin-pie spice in a large bowl.
In a separate bowl, whisk milk, vanilla, and egg.
Stir the wet mixture into the dry ingredients until just combined.
Fold in pumpkin purée and ½ cup chocolate chips. Let the batter rest while the griddle heats to medium.
Spray the griddle. Portion batter using approximately ¼ cup per pancake and sprinkle with remaining chocolate chips.
Cook until bubbles appear and pop, edges set, and bottoms are evenly browned. Flip and cook until the second side is lightly browned and the chocolate melts.
Hold finished pancakes on a lightly foil-covered baking sheet in a 200°F oven.
Serve warm with maple syrup, if desired.